Antenna array with independently rotated radiating elements

ABSTRACT

An antenna array that can include a plurality of antenna cells positioned in a global coordinate system of the antenna array. Each of the plurality of antenna cells has a respective local coordinate system and can include a radiating element having a predetermined angle of rotation defined in the global coordinate system and an antenna port coupled to the radiating element, the antenna port being positioned at a particular set of coordinates in the respective local coordinate system. The particular set of coordinates of the antenna port of each of the plurality of antenna cells can be the same.

TECHNICAL FIELD

This relates generally to antennas and more particularly to an antennaarray with rotated radiating elements.

BACKGROUND

An antenna array (or array antenna) is a set of multiple radiatingelements that work together as a single antenna to transmit or receiveradio waves. The individual radiating elements (often referred to simplyas “elements”) can be connected to a receiver and/or transmitter bycircuitry that applies appropriate amplitude and/or phase adjustment ofsignals received and/or transmitted by the radiating elements. When usedfor transmitting, the radio waves radiated by each individual radiatingelement combine and superpose with each other, adding together(interfering constructively) to enhance the power radiated in desireddirections, and cancelling (interfering destructively) to reduce thepower radiated in other directions. Similarly, when used for receiving,the separate received signals from the individual radiating elements arecombined with the appropriate amplitude and/or phase relationship toenhance signals received from the desired directions and cancel signalsfrom undesired directions.

An antenna array can achieve an elevated gain (directivity) with anarrower beam of radio waves, than can be achieved by a single antenna.In general, the larger the number of individual antenna elements used,the higher the gain and the narrower the beam. Some antenna arrays (suchas phased array radars) can be composed of thousands of individualantennas. Arrays can be used to achieve higher gain (which increasescommunication reliability), to cancel interference from specificdirections, to steer the radio beam electronically to point in differentdirections and/or for radio direction finding.

SUMMARY

One example relates to an antenna array that can include a plurality ofantenna cells positioned in a global coordinate system of the antennaarray. Each of the plurality of antenna cells has a respective localcoordinate system and can include a radiating element having apredetermined angle of rotation defined in the global coordinate systemand an antenna port coupled to the radiating element, the antenna portbeing positioned at a particular set of coordinates in the respectivelocal coordinate system. The particular set of coordinates of theantenna port of each of the plurality of antenna cells can be the same.Additionally, the predetermined angle of rotation of the radiatingelement of a first antenna cell of the plurality of antenna cells is afirst rotation angle in the global coordinate system. The predeterminedangle of rotation of the radiating element of a second antenna cell ofthe plurality of antenna cells can be a second rotation angle in theglobal coordinate system. The second rotation angle can be differentthan the first rotation angle.

Another example relates to a multi-layer printed circuit board (PCB)that can include a beam-forming layer having a plurality of traces thatform a beam-forming network (BFN), wherein the beam-forming network iscoupled to a plurality of antenna ports forming vias extending away fromthe beam-forming network (BFN). The BFN can include a plurality ofcombiners/dividers that convert between an input signal and a pluralityof sub-signals. Each of the plurality of sub-signals can have an equalpower and an array of phases. Each of the plurality of sub-signals canbe communicated to an antenna port of the plurality of antenna ports.The multi-layer PCB can also include a plurality of antenna cells beingpositioned in a global coordinate system of the multi-layered PCB toform a regular tiling pattern. Each of the plurality of antenna cellscan have a respective local coordinate system. Each antenna cell caninclude a radiating layer comprising a radiating element that has apredetermined angle of rotation in the global coordinate system. Eachantenna cell can also include a feedline layer that can have a feedlinethat couples a corresponding antenna port of the plurality of antennaports to the radiating element. Each antenna port can intersect with thefeedline layer at a particular set of coordinates in the respectivelocal coordinate system. The particular set of coordinates for each ofthe plurality of antenna cells can be the same. Additionally, thepredetermined angle of rotation of the radiating element of a firstantenna cell of the plurality of antenna cells can be a first rotationangle in the global coordinate system. The predetermined angle ofrotation of the radiating element of a second antenna cell of theplurality of antenna cells can be a second rotation angle in the globalcoordinate system, the second rotation angle can be different than thefirst rotation angle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a plan view of an antenna array with a plurality ofantenna cells.

FIG. 2 illustrates a plan view of a beam-forming network (BFN) incommunication with the antenna array of FIG. 1.

FIG. 3 illustrates an extended plan view of a BFN.

FIG. 4 illustrates an example of a BFN array.

FIG. 5 illustrates plan view of another antenna array with a pluralityof antenna cells.

FIG. 6 illustrates a plan view of another BFN in communication with theantenna array of FIG. 5.

FIG. 7 illustrates another extended plan view of another BFN.

FIG. 8 illustrates plan view of yet another antenna array with aplurality of antenna cells.

FIG. 9 illustrates a plan view of yet another BFN in communication withthe antenna array of FIG. 8.

FIG. 10 illustrates an extended plan view of yet another BFN.

FIG. 11 illustrates a stack-up view of a multi-layer printed circuitboard for implementing a system with an antenna array and a BFN.

FIG. 12 illustrates a block diagram of a system that implements anantenna array and a BFN.

DETAILED DESCRIPTION

This disclosure describes an antenna array with a plurality of antennacells positioned in a global coordinate system, and each antenna cellhas its own respective local coordinate system. Each antenna cell in theantenna array can have a radiating element (e.g., a slot-coupled patchantenna) with a predetermined angle of rotation in the global coordinatesystem. Moreover, each antenna cell can have an antenna port that can becoupled to the corresponding radiating element. The antenna port can bepositioned at a particular set of coordinates in the respective localcoordinate system. In some examples, this particular set of coordinatescan be the same for each respective local coordinate system of theantenna cells. In other words, in some examples, the angle of rotationof each antenna cell in the plurality of antenna cells in the globalcoordinate system does not change the position of the antenna port ineach respective local coordinate system.

The antenna port of each of the plurality of antenna cells can becoupled to a beam-forming network (BFN) through an integrated circuit(IC) chip, as explained herein. By positioning each antenna port in thesame coordinates in each local coordinate system, the design of the BFNcan be simplified. In particular, the positions of the antenna ports canbe regular, such that the BFN can be designed systematically andindependent of the angle of rotation of the radiating elements of theantenna cells. Additionally, rotation of the antenna elements canimprove polarization purity. In other words, rotation of the antennaelements increases the ratio of a desired polarization componentrelative to an undesired component.

FIG. 1 illustrates a plan view of an example of an antenna array 100with a plurality of antenna cells 102. The antenna array 100 can beimplemented, for example, as a phased array antenna. The antenna cells102 can be arranged in a regular tiling pattern. The antenna array 100can be formed on a top layer and/or region of a multi-layer printedcircuit board (PCB), which can alternatively be referred to as amulti-layer printed wire board (PWB). For purposes of simplification ofexplanation, some layers are omitted and/or or illustrated as beingtransparent. In the present example, there are twelve (12) antenna cells102, but in other examples, there can be more or less antenna cells 102.In fact, in some examples, there can be one-hundred, one-thousand ormore antenna cells 102. Each of the twelve (12) antenna cells arelabeled A-L. Accordingly, a given antenna cell 102 can be identified andreferenced specifically. For instance, a first antenna cell 102 can bereferenced as “antenna cell A 102”, and an eighth antenna cell can bereferenced as “antenna cell H 102”. The antenna cells B-L 102 can alsobe referenced in this manner.

In the example illustrated, each antenna cell 102 has a hexagonal shape.In other examples, other shapes can be employed to implement theplurality of antenna cells 102, including shapes such as squares,rectangles or rhombuses that provide regular tiling.

The antenna array 100 includes a global coordinate system 104 thatdefines a global position for the entire antenna array 100. Moreparticularly, the global coordinate system 104 identifies a relativeposition of each of the plurality of antenna cells 102. Each of theantenna cells 102 can have a predetermined angle of rotation in theglobal coordinate system 104. Additionally, each of the antenna cells102 can include a radiating element 106 with a predetermined angle ofrotation in the global coordinate system 104 that may be different (orthe same) as the angle of rotation of the antenna cell 102 in the globalcoordinate system 104. In other words, the angle of rotation in theglobal coordinate system 104 of the radiating element 106 in a givenantenna cell 102 can be selected independently of the angle of rotationin the global coordinate system 104 of the antenna cell 102.

Each of the plurality of the antenna cell 102 can have a predeterminedangle of rotation in the global coordinate system 104. Additionally,each antenna cell 102 can include a local coordinate system. In theexample illustrated in FIG. 1, an origin of each local coordinate systemis positioned at a given vertex of the corresponding antenna cell 102.As an example, the local coordinate system for antenna cell A 102 islabeled as X_(A), Y_(A) to denote respective X and Y axes for the localcoordinate system of the antenna cell A 102. Antenna cells B-H arelabeled in a similar manner.

As described herein, each radiating element 106 includes a plurality ofconstituent structural components. In particular in the antenna array100, each radiating element 106 can include N number of slot elements110, where N is an integer greater than or equal to one (1) and ametallic patch radiator 114. Each slot element 110 can have an ‘H’ ordumbbell shape. Moreover, although in the illustrated and describedexample the radiating element 106 includes the N number of slot elements110 and the metallic patch radiator 114, other types of radiators forthe radiating element 106 are possible. In the example illustrated,there are two (2) slot elements 110, which can be individuallyreferenced with a subscript number. More particularly, in theillustrated example, each radiating element includes a first slotelement 110 ₁ and a second slot element 110 ₂ that are orthogonallyorientated with respect to each other. In other words, the first slotelement 110 ₁ can have a predetermined angle of rotation in the globalcoordinate system 104 and the second slot element 110 ₂ can be rotatedby 90 degrees relative to the first slot element 110 ₁. Thus,collectively, the first slot element 110 ₁ and the second slot antenna110 ₂ can have a predetermined angle of rotation in the globalcoordinate system 104 that can define the predetermined angle ofrotation of the radiating element 106 for the antenna cell 102.Additionally, in some examples, there can be more or less slot elements110 than the first slot element 110 ₁ and the second slot element 110 ₂.The angle of rotation in the global coordinate system 104 can be definedrelative to a particular structural element or a set of elements of agiven antenna cell 102, such as, but not limited to a port 118 (ormultiple ports 118). Similarly, in such a situation, the same particularstructural element or set of element in other antenna cells 102 can beemployed to define the angle of rotation of the other antenna cells 102.In other words, the angle of rotation in the global coordinate system102 is defined in the same manner across each of the A-L antenna cells102.

In some examples, the angle of rotation in the global coordinate system104 for each radiating element 106 can be, for example one of 0 degrees,+/−30 degrees, +/−90 degrees and +/−150 degrees. In other examples,other angles of rotation in the global coordinate system 104 may beused. Moreover, the pattern of the angle of rotation of the radiatingelements 106 of antenna cells 102 can vary based on desired operationalcharacteristics of the antenna array 100. For example, it can bedesirable to select a pattern for the antenna elements 106 that providesa high degree of polarization purity in a main beam for scanning inmultiple directions and maintaining side lobes of a radiation patternbelow a certain level.

The first slot element 110 ₁ and the second slot element 110 ₂ can bedesigned to communicate signals without substantially affecting therelative phase difference between signals of the first slot element 110₁ and the second slot element 110 ₂. For example, each radiating element106 of each respective antenna cell 102 can be designed to communicatecircularly polarized signals. For example, the first slot element 110 ₁of the radiating element 106 can be designed to communicate signals witha first linear polarization and the second slot element 110 ₂ of theradiating element 106 can be designed to communicate signals with asecond polarization. As one example, the first polarization can beoffset relative to the second polarization. Additionally, as noted,there are examples where there is only one slot element 110 for eachradiating element 106 and/or other types of radiators are employed forthe radiating element 106. In these situations, the radiating element106 can also be designed to communicate signals circular polarization orwith other polarizations, such as linear or elliptical polarization.

Moreover, as noted, the radiating element 106 of each antenna cell 102can include a metallic patch radiator 114 that can overlay the firstslot element 110 ₁ and the second slot element 110 ₂. The metallic patchradiator 114 can overlay a center of the antenna cells 102. In someexamples, the metallic patch radiator 114 can be formed on an uppersurface of the antenna array 100. In such a situation, the metallicpatch radiator 114 can be formed by etching away a portion a (top) thinmetal layer, with the un-etched portion forming the metallic patchradiator 114.

For purposes of simplification of explanation the terms “overlay”,“overlaying”, “underlay” and “underlaying” (and derivatives) areemployed throughout this disclosure to denote a relative position of twoadjacent surfaces in a selected orientation. Additionally, the terms“top” and “bottom” are employed throughout this disclosure to denoteopposing surfaces in the selected orientation. Similarly, the terms“upper” and “lower” are employed to denote relative positions in theselected orientation. In fact, the examples used throughout thisdisclosure denote one selected orientation. However, in the describedexamples, the selected orientation is arbitrary, and other orientationsare possible (e.g., upside down, rotated by 90 degrees, etc.) within thescope of the present disclosure.

Each antenna cell 102 can include N number of ports 118. Each port 118can electrically couple a BFN to a corresponding slot element 110. Thus,in the illustrated example, each antenna cell 102 can include a firstport 118 ₁ and a second port 118 ₂. Each antenna cell 102 can alsoinclude N number of feedlines 122 formed in a feedline layer (conductivetraces) that intersects with a corresponding port 118 at a particularset of coordinates in the corresponding local coordinate system.Moreover, each feedline 122 can connect each slot element 110 with acorresponding port 118. More particularly, in the example illustrated inFIG. 1, a first feedline 122 ₁ (a conductive trace) can connect a firstport 118 ₁ with a first slot element 110 ₁. Similarly, a second feedline1222 (a conductive trace) can connect a second port 118 ₂ and a secondslot element 110 ₂. Each feedline 122 in a given antenna cell 102 canhave the same length. Thus, the first feedline 122 ₁ and the secondfeedline 122 ₂ of the antenna cell A 102 can be the same length. In someexamples, the feedlines 122 of each different antenna cells 102 can havethe same lengths. To offset (counteract) the effects of rotation in eachantenna cell 102, additional phase adjustment (e.g., through subsequentor prior signal conditioning, as described herein) can be applied tosignals communicated by particular antenna cells 102. As an example,antenna cell A 102 and antenna cell D 102 can have feedlines 122 thatare the same length, but signals communicated with antenna cell A 102and antenna cell D 102 have different phases. The phase adjustment canbe employed to offset for these different phases.

In some examples, each port 118 can be positioned near a perimeter(e.g., near a vertex) of the corresponding antenna cell 102.Accordingly, in the plan view illustrated by FIG. 1, each port 118 islocated between the corresponding radiating element 106 and theperimeter of the corresponding antenna cell 102. In the exampleillustrated by the antenna array 100 of FIG. 1, the first port 118 ₁ andthe second port 118 ₂ are positioned near vertices of the antenna cell102. Additionally, the first port 118 ₁ and the second port 118 ₂ areseparated by the given (single) vertex that includes the origin of thelocal coordinate system. Accordingly, in some examples, each set ofports 118 for a given antenna cell 102 can be positioned at a same setof local coordinates. In other words, the first port 118 ₁ for eachantenna cell 102 can be positioned at the same set of local coordinatesin each of the antenna cells A-H 102. Similarly, the second port 118 ₂for each antenna cell 102 can be positioned at the same set of localcoordinates of each of the antenna cells A-L. Alternatively, in otherexamples, the position of each of the N number of ports can vary in thelocal coordinates of each antenna cell 102.

Each of the N number of ports 118 in each antenna cell 102 can be formedas a via (also referred to as a plated through hole) that extendsthrough one or more layers to IC chips and/or the BFN, depending on thedesign of the BFN. In this manner, each of the illustrated ports 118(including the first port 118 ₁ and the second port 118 ₂) of eachantenna cell 102 can represent a terminal of the via. In some examples,each port 118 can be considered as a long transition through the wholemulti-layer PCB, on which the antenna array 100 can be formed.Additionally or alternatively, the N number of ports 118 can be othertypes of interfaces for communicating signals between the BFN and eachantenna cell 102. Positioning each port 118 near a perimeter of theantenna cell 102 and away from the radiating element 106 of the antennacell 102 (positioned near a center) can reduce electromagnetic coupling.In some examples, each port 118 (or some subset thereof) can beenvironed by a plurality of isolation vias 130 positioned equidistant toa corresponding port 118, which can alternatively be referred to asshielding vias. In other examples, the plurality of isolation vias 130can be positioned at differing distances to a corresponding port 118.The isolation vias 130 can mimic co-axial shielding for the port 118.For purposes of simplification of illustration, only some of theisolation vias 130 are labeled. The isolation vias 130 can extend fullyor partially between the plurality of antenna cells 102 of the antennaarray 100 and the BFN. The antenna array 100 can be designed such thateach port 118 is in close proximity to five (5) isolation vias 130.

As illustrated, each port 118 of a given antenna cell 102 can bepositioned near two other ports 118 on two other antenna cells 102.Additionally, each of the isolation vias 130 can be located near avertex and/or on a perimeter of an antenna cell 102. In this manner, thesame isolation via 130 can provide shielding for multiple ports 118. Forexample, an isolation via 130 located at a vertex common to antennacells B, D and E 102 can concurrently provide shielding for the firstport 118 ₁ of antenna cells B, D and E 102. Accordingly, by rotatingeach antenna cell 102 in the global coordinate system 104 in the mannerillustrated, the total number of isolation vias 130 needed to provideshielding on five (5) sides of each port 118 can be reduced.

As noted, each antenna cell 102 can have an angle of rotation in theglobal coordinate system 104. In some examples, a given antenna cell 102can be rotated relative to another antenna cell 102. For instance,antenna cell B 102 can be rotated in the global coordinate system 104relative to antenna cell A 102 by 120 degrees.

Additionally, although the radiating elements 106 of each antenna cell102 have an angle of rotation defined in the global coordinate system104, each radiating element 106 can also have a local angle of rotationdefined in the corresponding local coordinate system. In such asituation, the local angle of rotation for a radiating element 106 of agiven antenna cell 102 can be offset from the local angle of rotationfor a radiating element 106 of another antenna cell 102. For example,the local angle of rotation of the radiating element 106 in the localcoordinate system of the antenna cell B 102 can be offset from the localangle of rotation of the radiating element 106 in the local coordinatesystem of the antenna cell A 102 by 120 degrees.

Further still, in a given example, a given antenna cell 102 can have anangle of rotation in the global coordinate system 104 that is differentthan the angle of rotation in the global coordinate system 104 foranother antenna cell 102. Additionally, in the given example, theradiating elements 106 of the given and the other antenna cells 102 canhave the same angle of rotation in the global coordinate system 104. Forexample, antenna cell D 102 and antenna cell G 102 can have differentangles of rotation in the global coordinate system 104. However, theradiating element 106 of the antenna cells D and G 102 can have the sameangle of rotation in the global coordinate system 104 since theradiating element 106 of antenna cells D and G 102 can have differentangles of rotation in the respective local coordinate systems. Asdiscussed herein, to account for the different angles of rotation of theantenna cells 102 in the global coordinate system 104, phases of signalscommunicated by the radiating elements 106 of the antenna cells can beadjusted.

In some examples, each antenna cell 102 can be a member of a group ofantenna cells 102. In some examples, a given group of antenna cells 102can share an intersecting point (e.g., such as a common vertex inexamples where the antenna cells 102 are polygons). Accordingly, in theexample illustrated in FIG. 1, a first group of antenna cells could beformed with antenna cells A, B and C 102. Additionally, a second groupof antenna cells 102 can be formed with antenna cells D, F and G 102.The antenna array 100 can be designed such that the rotation angle ofeach radiating element 106 in a given group of antenna cells 102 definesa group rotation pattern. As used herein, the term “group rotationpattern” denotes a specific set of rotations of the radiating element106 for each member of the group. As one example, if the radiatingelement 106 of the antenna cell A 102 has a rotation angle of 0 degrees,the antenna cell B 102 has a rotation angle of 30 degrees and theantenna cell C 102 has an angle of rotation of −30 degrees, the combinedset of 0 degrees, 30 degrees and −30 degrees in the relative locationsof cells A, B and C 102 defines the group rotation pattern. In someexamples, the antenna array 100 can be designed such that adjacentgroups of antenna cells have different group rotation patterns.Additionally, in some examples, it can be desirable to avoid repeatingthe same angle of rotation of the radiating element 106 for a group ofantenna cells 102 throughout the antenna array 100 to avoid elevatedside lobes for the overall radiation pattern of the antenna array 100.

In operation, the antenna array 100 can communicate signals between freespace and the BFN. In particular, in a receiving mode, anelectromagnetic (EM) signal transmitted in free space can be provided tothe N number of slot elements 110 by the corresponding metallic patchradiator 114. The N number of slot elements 110 on the correspondingantenna cell 102 can convert a radiated EM signal into a guided EMsignal. Each of the N number of feedlines 122 can provide the electricalsignals to the corresponding port 118. Each port 118 can provide theelectrical signal to an IC chip coupled to the BFN. In some examples,the IC chip can be an integrated component of the BFN. In otherexamples, the IC chip and the BFN can be separate, but coupledcomponents. The IC chip can adjust (e.g., combine, amplify and/or phaseadjust) the electrical signal and provide an adjusted electrical signalto the BFN. The BFN can combine the adjusted electrical signal to form areceived beam signal and provide the received beam signal to an externalsystem for further processing and/or decoding.

In a transmitting mode, an electrical signal can be provided from theBFN to the IC chips. The IC chips can adjust the signals and provide theadjusted signals to the N number of ports 118 at each of the antennacells 102. The electrical signals can be provided to the correspondingslot elements 110 of the antenna cells 102. The slot elements 110 canconvert a guided EM signal into a radiated EM signal that is transmittedto the corresponding metallic patch radiator 114 of each antenna cell102. The patch antennas 114 can transmit the EM signal into free space.

In some examples, the antenna array 100 can be designed to operateexclusively in either the receiving mode or the transmitting mode. Inother examples, the antenna array 100 can operate in a half-duplexingmode, such that the antenna array 100 can operate in the receiving modeand the transmitting mode periodically and/or asynchronously. In stillother examples, the antenna array 100 can operate in a full-duplexingmode, such that the antenna array 100 can operate in the receiving modeand the transmitting mode concurrently.

By implementing the antenna array 100, the radiating elements 106 ofeach antenna cell 102 can be selected to have an angle of rotation inthe global coordinate system 104 that is independent on the location ofthe N number of ports 118 at each antenna cell 102. Stated differently,the N number of slot elements 110 for each antenna cell 102 (namely, thefirst slot element 110 ₁ and the second slot element 110 ₂) can berotated in the global coordinate system 104 without necessitating achange in the location of the corresponding N number of ports 118,namely the first port 118 ₁ and the second port 118 ₂. Rather, eachantenna cell 102 can be designed such that the location of the ports 118varies based on the angle of rotation of the entire individual antennacell 102, and that the angle of rotation of the slot elements 110 canvary independently of the angle of rotation of the antenna cell 102.Accordingly, the antenna array 100 can be designed such that thelocation of the ports 118 occurs at regular, predetermined positions inthe global coordinate system 104. In this manner, as described herein,the BFN underlying the antenna array 100 can be designed independentlyfrom the antenna array 100. In fact, as explained in detail, the BFNunderlying the antenna array 100 can have a systematic design.

FIG. 2 illustrates a plan view of an example of a BFN 200 that can beemployed to adjust signals communicated with the antenna array 100 ofFIG. 1. The BFN 200 can be formed on an interior layer (e.g., a BFNlayer) of the multi-layer PCB employed for the antenna array 100. TheBFN layer can include a plurality of traces (conductive traces). Forpurposes of simplification of explanation, the same reference numbersare employed in FIGS. 1 and 2 to denote the same structure. The BFN 200can be partitioned into a plurality of BFN cells 202 that are eachrotated in the global coordinate system 104. As noted, the BFN 200 canunderlay the antenna array 100 of FIG. 1. Moreover, each BFN cell 202can have the same size and shape (e.g., a hexagon) as an overlayingantenna cell 102. Accordingly, the BFN cells 202 are labeled A-L tocorrespond to the overlaying antenna cells 202. Thus, BFN cell A 202 canunderlay antenna cell A 202. Each BFN cell 202 can have the same localcoordinate system as the corresponding antenna cell 102. Accordingly,BFN cell A 202 can have the same local coordinate system as the antennacell A 202.

Each BFN cell 202 can include N number of ports 118. In the exampleillustrated by the BFN 200, each BFN cell 202 includes a first port 118₁ and a second port 118 ₂. Each port 118 can be representative of aterminal of a via to a port illustrated in the antenna array 100. Forexample, the first port 118 ₁ of BFN cell A 202 can represent a terminalend of the via corresponding to the first port 118 ₁ of the antenna cellA 102. Each of the N number of ports 118 can be at a same set ofcoordinates in each respective local coordinate system. Each of the Nnumber of ports 118 can extend away from the BFN 200 and toward theantenna array 100. As explained with respect to the antenna array 100,each of the N number of ports 118 can be at a same set of coordinates ineach local coordinate system.

Each of the N number of ports 118 can be environed by a plurality ofisolation vias 130, only some of which are labeled. The isolation vias130 can correspond to the isolation vias 130 of FIG. 1. In the exampleillustrated, there are five (5) isolation vias in close proximity toeach port 118. However, in other examples, there can be more or lessisolation vias 130. Moreover, the isolation vias 130 can be sharedbetween ports 118 on different BFN cells 202, thereby reducing theoverall number of isolation vias 130 needed to provide sufficientshielding for the ports 118. Additionally, in some examples, some of theisolation vias 130 can extend only partially between the BFN 200 and theantenna array 100 of FIG. 1.

The BFN 200 can include an input/output (I/O) port 206 that can becoupled to an external system or to another BFN of additional antennacells in a manner described herein. The I/O port 206 can be coupled to afirst stage combiner/divider 208, which can be coupled to two (2) secondstage combiners/dividers 210. In this manner, the first stagecombiner/divider 208 and the second stage combiners/dividers 210 have acascade (hierarchical) relationship. In other words, the first stagecombiners/dividers 208 can operate as a first stage of the BFN 200, andthe second beam forming stage combiners/dividers 210 can operate assecond beam forming stage of the BFN 200. Each of the second stagecombiners/dividers 210 can be coupled to two (2) 1-to-3combiners/dividers 212, which can operate as a third beam forming stageof the BFN 200. Each 1-to-3 combiner/divider 212 can be positioned at anintersection of three (3) BFN cells 202.

The second stage combiners/dividers 210 can be symmetrically arrangedrelative to the first stage combiners/dividers 208. The second stagecombiners/dividers 210 can be fabricated on different layers of the BFN200 than the BFN cells 202. For purposes of simplification ofillustration, different line weights and/or patterns are employed todenote different layers of the BFN. A set of BFN cells 202, 1-to-3combiner/divider 212 and a second stage divider 210 can define a beamforming stage that has a local coordinate system. In this manner, eachbeam forming stage (a combination of BFN cells 202, 1-to-3combiner/divider 212 and a second stage divider 210) can have the samegeometric shape in the local coordinate system. Moreover, the beamforming stages can be rotated in the global coordinate system 104 tofacilitate the systematic design of the BFN 200. Furthermore, thesystematic nature of the beam forming stages of the BFN 200 having thesame geometric shape can also be present at additional stages across asub-array, such as shown in FIG. 3. In other words, in FIG. 3, thegeometric shape of the first three beam forming stages have the samegeometric shape as other instances of the first three beam formingstages in an array. Thus, taken one step further in some examples, thegeometric shape of a first four stages can have the same geometric shapeas other first four stages in the array. Accordingly, each instance ofthe beam forming stage has the same geometric shape as another instanceof the beam forming stage of the same stage. In other words, a givenbeam forming stage of the BFN 200 has the same geometric shape asanother beam forming stage of the BFN 200 if the given and the otherbeam forming stages are the same stage (e.g., both the given and theother stages are first stages, second stages, etc.).

As used herein, the concept of each beam forming stage having the samegeometric shape indices that the beam forming stage has the same shapewith mirroring and/or rotation in the global coordinate system, such asillustrated in FIG. 3. Moreover, two beam forming stages can also beconsidered to have the same geometric shape if the two beam formingstages are symmetric about one or more lines of symmetry. Still further,two beam forming stages are considered to have the same geometric shapeif the two beam forming stages are substantially identical withoutmirroring and/or rotation.

Each BFN cell 202 can be coupled to an integrated circuit (IC) chip 220(or multiple IC chips) and/or other circuits that can adjust signals.The IC chip 220 can be mounted on a bottom of the multi-layer PCB thatimplements the BFN. Thus, each IC chip 220 can underlay the BFN 200.Each IC chip 220 can be coupled to a 1-to-3 combiner/divider 212 and tothe N number of ports 118 of the BFN cell 202. As an example, the firstport 118 ₁ and the second port 118 ₂ of the BFN cell A 102 can becoupled to the IC chip 220 of the BFN cell A 202, which is coupled tothe 1-to-3 combiner/divider 212 positioned between BFN cell A 202, BFNcell B 202 and BFN cell C 202. Each IC chip 220 can adjust electricalsignals. Such adjustment can include amplifying, phase adjusting,combining and/or dividing signals. In some examples, the IC chip 220 ofthree different BFN cells 202, such as BFN cells A, B and C 202 canadjust signal communicated with the corresponding 1-to-3 combiner 212 byan amount to compensate for rotation of radiating elements, such as theradiating elements 106 of FIG. 1.

The combiners/dividers described herein can execute one or both adividing operation and a combining operation that convert between aninput/output signal and a plurality of sub-signals. In the examplesdescribed herein, each dividing operation executed can divide an inputsignal into a plurality of sub-signals that have equal power and anarray of phases. Conversely, in the examples described herein, in acombining operation, multiple sub-signals with an array of phases can becombined into a single combined signal.

In the transmitting mode, the first stage combiners/divider 208 can bedesigned to divide (e.g., equally or unequally, in-phase orout-of-phase) a signal input to the I/O port 206 into sub-signals thatare provided to the second stage combiners/dividers 210. Similarly, inthe transmit mode, each second stage combiner/divider 210 can divide(e.g., equally or unequally, in-phase or out-of-phase) a signal receivedfrom the first stage combiner/divider 208 into two (2) sub-signals thatare coupled to 1-to-3 combiners/dividers 212. Each 1-to-3combiner/divider can divide (e.g., equally or unequally, in-phase orout-of-phase) the signal to three (3) sub-signals that are each providedto an IC chip 220 corresponding to three (3) different BFN cells 202.For example, the 1-to-3 combiner/divider 212 positioned at theintersection of BFN cells A, B and C 202 can provide a signal to the ICchip 220 of BFN cells A, B and C 202.

Continuing in the transmitting mode, the IC chip 220 of each BFN cell202 can be designed/programmed to adjust (amplify, phase adjust and/ordivide) the signal into N number of signals that are provided to the Nnumber of ports 118. For example, the IC chip 220 of the BFN cell 202can be designed to amplify and divide the signal from the 1-to-3combiner/divider 212 into two (2) sub-signals that are provided to thefirst port 118 ₁ and the second port 118 ₂ of the BFN cell A 202. Thesignals can then be transmitted in the manner described with respect toFIG. 1.

In the receiving mode, signals received at each of the N number of ports118 in each of the BFN cells 202 can be combined and adjusted (amplifiedand/or phase adjusted) by the corresponding IC chip 220 and provided toa corresponding 1-to-3 combiner/divider 212. As an example, the IC chip220 corresponding to BFN cells A, B and C 202 can each provide anadjusted signal to the 1-to-3 combiner/divider 212 at the intersectionof the BFN cells A, B, and C 202.

Continuing in the receiving mode, each of the 1-to-3 combiners/dividers212 can combine adjusted sub-signals and provide a combined signal to acorresponding second stage combiner/divider 210. In turn, the secondstage combiners/dividers 212 can again combine the sub-signals andprovide the combined signal to the first stage combiner/divider 208. Thefirst stage combiner/divider 208 can combine the sub-signals, and outputthe combined signal at the I/O port 206.

Similar to the antenna array 100 of FIG. 1, the BFN 200 can be designedto operate exclusively in the transmitting mode or the receiving mode.Additionally, the BFN 200 can be designed to switch periodically and/orasynchronously between the transmitting mode and the receiving mode.Still further, in some examples, the BFN 200 can operate in thetransmitting mode and the receiving mode concurrently.

As illustrated with the antenna array 100 of FIG. 1 and the BFN 200 ofFIG. 2, the antenna cells 102 and the BFN cells 202 can communicatethrough the N number of ports 118. Moreover, the antenna array 100 canbe designed such that the radiating elements 106 can be rotatedindependently from the location of the ports 118. Accordingly, the angleof rotation of the radiating elements 106 does not necessarily impactthe physical layout of the BFN 200. Therefore, the BFN 200 and theantenna array 100 can be designed independently based on predeterminedpositions of each of the N number of ports 118 for each BFN cell 202 andeach antenna cell 102. Thus, the overall design of the BFN 200 and theantenna array 100 can be simplified. In fact, the systematic design ofthe BFN 200 further demonstrates possibilities of a BFN when the BFN 200is matched with the antenna array 100 of FIG. 1 (or a variant thereof).In particular, a designer of the BFN can be unburdened with concern forthe individual placement of the ports 118. Instead, the ports 118 appearin regular, predictable positions that are readily accommodated by thevarious types of the antenna cells 102 of the antenna array 100.

In some examples, the BFN 200 can be designed with systematicallysymmetric modules that are scalable to accommodate nearly any number oflevels of hierarchy. In particular, although the BFN 200 is describedwith two (2) stages of combiners/dividers, namely the first stagecombiner/divider 208 and the second stage combiners/dividers 208, theBFN 200 illustrated can be employed as module or circuit to implement alarger scale BFN, including the BFN 300 illustrated in FIG. 3.

In the BFN 300, four (4) instances of the BFN 200 of FIG. 2 areconnected in a cascade (hierarchical) arrangement. In particular, an I/Oport 302 is coupled to a first stage combiner/divider 304, which iscoupled to two (2) second stage combiners/dividers 306. Each secondstage combiner/divider 306 can be coupled to a port 206 of an instanceof the BFN 200 (a module of the BFN 300). In this manner, the four (4)instances of the BFN 200 are connected together in a cascadearrangement. Further, in other examples, multiple instances of the BFN300 can be coupled in another cascade arrangement, thus providing asystematic design for the BFN 300. Further, in some examples, multipleBFNs 300 can be included in a BFN array, such as the BFN array 320illustrated in FIG. 4

In the BFN array 320, three (3) instances of the BFN 300 of FIG. 3 arearranged in an array. Moreover, although the instances of the BFN 300are not coupled in FIG. 4, in other examples of the BFN array 320, eachinstance of the BFN 300 or some subset thereof can be coupled to provideanother cascade (hierarchical) arrangement.

FIG. 5 illustrates another plan view of an example of an antenna array400. The antenna array 400 can be formed on a top layer and/or region ofa multi-layer PCB. The antenna array 400 can include a plurality ofantenna cells 402 arranged in a tile pattern. Each antenna cell 402 canhave a square shape. The example illustrated by the antenna array 400includes eight (8) antenna cells 402, labeled as antenna cells A-H. Eachof the plurality of antenna cells 402 can be arranged in a globalcoordinate system 404. Moreover, each antenna cell 402 can include aninstance of a radiant element 406. Each radiating element 406 caninclude N number of slot elements 408. In the example illustrated, eachantenna cell 402 includes two orthogonally positioned slot elements 408,namely a first slot element 4081 and a second slot element 4082. Eachradiating element 406 can also include a metallic patch radiator 410.

Each of the N number of slot elements 408 can be rotated in the globalcoordinate system 404. Additionally, each antenna cell 402 can include alocal coordinate system labeled with an origin axis positioned near acorner of each antenna cell 402. Each antenna cell 402 can include Nnumber of ports 414 that couple each respective antenna cell 402 to aBFN that underlays the antenna array 400. Each port 414 can include avia to couple each respective antenna cell 402 to the BFN. Moreover,each port 414 in FIG. 5 can be representative of a terminal of the via.In the illustrated example, each antenna cell includes two (2) ports414, namely a first port 414 ₁ and a second port 414 ₂. Additionally, inthe example illustrated, each of the first port 414 ₁ and the secondport 414 ₂ can be positioned at adjacent corners of the antenna cells402. As used herein, “adjacent corners” are defined as two corners thatshare a side of a polygon. Each antenna cell 402 can include N number offeedlines 416 that are formed on a feedline layer of the antenna array400. In the example illustrated, there are two (2) feedlines, namely afirst feedline 4161 and a second feedline 4162. Each feedline 416 cancouple a port 414 with a corresponding slot element 408. Each of the Nnumber of feedlines 416 of the antenna array 400 have the same length.Signals communicated with the radiating elements 406 can be phaseadjusted to compensate (counteract) the rotation of the radiatingelements 406.

Each of the ports 414 can be environed by a plurality of isolation vias415 positioned equidistant to a corresponding port 414. In the exampleillustrated, there are four (4) isolation vias 415 in close proximity toeach port 414. However, in other examples, there can be more or lessisolation vias 415. Moreover, the isolation vias 415 can be sharedbetween ports 414 on different antenna cells 402, thereby reducing theoverall number of isolation vias 415 needed to provide sufficientshielding for the ports 414. Additionally, in some examples, some of theisolation vias 415 can extend only partially between the BFN and theantenna array 400.

Each of the N number of ports 414 in each antenna cell 402 can bepositioned at a set of coordinates in a corresponding local coordinatesystem, which can be the same set of coordinates in each localcoordinate system. In such examples, the ports 414 can intersect thefeedline layer that contains the feedlines 416 at the set of coordinatesin the local coordinate system of each antenna cell 402. In other words,the first port 414 ₁ of the antenna cell A 402 can have the same set ofcoordinates in the corresponding local coordinate system as the firstport 414 ₁ of the antenna cell B 402. In this manner, the ports 414 canbe located at regular, predetermined positions throughout the antennaarray 400.

In some examples, the angle of rotation of each radiating element 406 inthe global coordinate system 404 can be 0 degrees, +/−90 degrees, +/−180degrees and +/−270 degrees. In other examples, other angles of rotationin the global coordinate system 104 are possible. Additionally, theantenna array 400 can operate in the same (or similar manner) as theantenna array 100 of FIG. 1. Accordingly, each antenna cell 402 of theantenna array 400 can be designed to communicate RF signals with freespace. In other words, the antenna array 400 can be designed to at leastone of transmit RF signals into free space and receive RF signals fromfree space. Such communicated signals can be adjusted by a BFN and (insome examples), IC chips, as explained herein.

FIG. 6 illustrates a plan view of an example of a BFN 500 that can beemployed to communicate with the antenna array 400 of FIG. 5. Someelements of the BFN 500 can be formed on an interior layer of themulti-layer PCB employed for the antenna array 400, and other elementscan be formed on an exterior layer of the BFN 500, such as a bottomlayer of the BFN 500. For purposes of simplification of explanation, thesame reference numbers are employed in FIGS. 5 and 6 to denote the samestructure. The BFN 500 can be partitioned into a plurality of BFN cells502 that are each rotated in the global coordinate system 404. As noted,the BFN 500 can underlay the antenna array 400 of FIG. 5. Moreover, eachBFN cell 502 can have the same size and shape (e.g., a square) as anoverlaying antenna cell 402. Accordingly, the BFN cells 502 are labeledA-H to correspond to the overlaying antenna cell 402 with the same labelA-H. Thus, BFN cell A 502 underlies antenna cell A 402. Each BFN cell502 can have the same local coordinate system as the correspondingantenna cell 402.

Each BFN cell 502 can include N number of ports 414. In the exampleillustrated by the BFN 500, each BFN cell 502 includes a first port 414₁ and a second port 414 ₂. Each port 414 can be representative of aterminal of a via to a port 414 illustrated in the antenna array 400. Asexplained with respect to the antenna array 400, each of the N number ofports 414 can be at a same set of coordinates in each respective localcoordinate system.

Each of the N number of ports 414 can be environed by a plurality ofisolation vias 415, only some of which are labeled. The isolation vias415 can correspond to the isolation vias 415 of FIG. 5. In someexamples, some of the isolation vias 415 can extend only partiallybetween the BFN 500 and the antenna array 400 of FIG. 5.

The BFN 500 can include an I/O port 506 that can be coupled to anexternal system. The I/O port 506 can be coupled to a first stagecombiner/divider 508, which can be coupled to two (2) second stagecombiners/dividers 510 through vias 512. In some examples, the vias 512can be shorter than the vias of the ports 414. Additionally, the firststage combiner/divider 508 and the second stage combiners/dividers 510have a cascade arrangement.

The second stage combiners/dividers 510 can be symmetrically arrangedrelative to the first stage 508. Moreover, in such a situation, BFNcells 502 and a second stage combiner/divider 510 can define a beamforming stage that has a local coordinate system. In this manner, eachbeam forming stage (a combination of BFN cells 502 and a second stagedivider 510) can have the same geometric shape in the local coordinatesystem. Moreover, each beam forming stage can be rotated in the globalcoordinate system 404.

Each BFN cell 502 can correspond to an IC chip 520 (or multiple ICchips) that can adjust signals. Each IC chip 520 can be positioned onthe bottom layer of the BFN 500. In some examples, each IC chip 520 canbe integrated with the BFN 500, and in other examples, each IC chip 520can be a separate component that communicates with the BFN 500. Each ICchip 520 can be coupled to a combiner/divider 510 and to the N number ofports 414 of the BFN cell 502. As some examples, each IC chip 520 canamplify, phase adjust, combine and/or divide signals.

The BFN 500 can operate in a manner similar to the BFN 200 of FIG. 2.Thus, the BFN 500 can operate in at least one of the transmitting modeand the receiving mode.

As illustrated with the antenna array 400 of FIG. 5 and the BFN 500 ofFIG. 6, the antenna cells 402 and the BFN cells 502 can communicatethrough the N number of ports 414. Moreover, the antenna array 400 canbe designed such that the slot elements 408 can be rotated independentlyfrom the location of the ports 414. Accordingly, the angle of rotationof the slot elements 408 does not necessarily impact the physical layoutof the BFN 500. Therefore, the BFN 500 and the antenna array 400 can bedesigned independently based on predetermined positions of each of the Nnumber of ports 414 for each BFN cell 502 and each antenna cell 402.Thus, the overall design of the BFN 500 and the antenna array 400 can besimplified.

In some examples, the BFN 500 can be designed systematically withsymmetric modules that are scalable to accommodate nearly any number oflevels. In particular, although the BFN 500 is described with two (2)stages of combiners/dividers, namely the first stage combiner/divider508 and the second stage of combiners/dividers 510, the BFN 500illustrated can be employed as a module or circuit to implement a largerscale BFN, including the BFN 600 illustrated in FIG. 7.

In the BFN 600, eight (8) instances of the BFN 500 of FIG. 6 areconnected in a cascade (hierarchical) arrangement. In particular, an I/Oport 602 is coupled to a first stage combiner/divider 604, which iscoupled to two (2) second stage combiners/dividers 606. Each secondstage combiner/divider 606 can be coupled to two (2) third stagecombiners/dividers 608. Each third stage combiner/divider 608 can becoupled to two instances of an input port 506 of an instance of the BFN500 (a module of the BFN 600). In this manner, the eight (8) instancesof the BFN 600 are connected together in a cascade arrangement. Further,in other examples, multiple instances of the BFN 600 can be coupled in acascade arrangement.

FIG. 8 illustrates another plan view of an example of an antenna array700. The antenna array 700 can be formed on a top layer and/or region ofa multi-layer PCB. The antenna array 700 can include a plurality ofantenna cells 702 that can be arranged in regular tiling pattern. Eachantenna cell 702 can have a square shape. The example illustrated by theantenna array 700 includes eight (8) antenna cells 702, labeled asantenna cells A-H. Each of the plurality of antenna cells 702 can bearranged in a global coordinate system 704. Moreover, each antenna cell702 can include an instance of a radiating element 706. Each radiatingelement 706 can include N number of slot elements 708. In the exampleillustrated, each antenna cell 702 includes two orthogonally positionedslot elements 708, namely a first slot element 7081 and a second slotelement 7082. Each radiating element 706 can also include a metallicpatch radiator 710.

Each of the N number of slot elements 708 can be rotated in the globalcoordinate system 704. Additionally, each antenna cell 702 can include alocal coordinate system labeled with an origin axis positioned near acorner of each antenna cell 702. Each antenna cell 702 can include Nnumber of ports 714 that couple each respective antenna cell 702 to aBFN that underlays the antenna array 700. In the illustrated example,each antenna cell include two (2) ports 714, namely a first port 7141and a second port 7142. Additionally, in the example illustrated, eachof the first port 7141 and the second port 7142 can be positioned atopposing corners of the antenna cells 702. In other words, the firstport 7141 and the second port 7142 are positioned cattycorner relativeto each other. Each port 714 can be environed by a plurality ofisolation vias 715 spaced equidistant from a corresponding port 714,only some of which are labeled. In the example illustrated, there arefour (4) isolation vias 715 in close proximity to each port 714.However, in other examples, there can be more or less isolation vias715. Moreover, the isolation vias 715 can be shared between ports 714 ondifferent antenna cells 702, thereby reducing the overall number ofisolation vias 715 needed to provide sufficient shielding for the ports714. Additionally, in some examples, some of the isolation vias 715 canextend only partially between the BFN and the antenna array 700.

Each antenna cell 702 can include N number of feedlines 716 formed on afeedline layer. In the example illustrated, there are two (2) feedlines716 in each antenna cell 702, namely a first feedline 7161 and a secondfeedline 7162. Each feedline 716 can couple a port 714 with acorresponding slot element 708. In some examples, the first feedline7161 and the second feedline 7162 within a given antenna cell 702 canhave the same length.

Each of the N number of ports 714 in each antenna cell 702 can bepositioned at a set of coordinates in a corresponding local coordinatesystem, which can be the same set of coordinates in each localcoordinate system. Accordingly, in some examples, the N number of ports714 in each antenna cell 702 can intersect the feedline layer at thesame set of coordinates in the corresponding local coordinate system.Consequently, the first port 7141 of the antenna cell A 702 can have thesame set of coordinates in the corresponding local coordinate system asthe first port 7141 of the antenna cell B 702. In this manner, the ports714 are located at regular positions throughout the antenna array 700.

In some examples, the angle of rotation of each radiating element 706 inthe global coordinate system 704 can be 0 degrees, +/−90 degrees, +/−180degrees and +/−270 degrees. In other examples, other angle of rotationsin the global coordinate system 704 are possible. The antenna array 700can operate in the same (or similar manner) as the antenna array 100 ofFIG. 1. Accordingly, each antenna cell 702 of the antenna array 700 canbe designed to communicate RF signals with free space. In other words,the antenna array 700 can be designed to at least one of transmit RFsignals into free space and receive RF signals from free space. Suchcommunicated signals can be adjusted by a BFN and (in some examples), ICchips, as explained herein.

FIG. 9 illustrates another plan view of an example of a BFN 800 that canbe employed to communicate with the antenna array 700 of FIG. 8. Somecomponents of the BFN 800 can be formed on an interior layer of themulti-layer PCB employed for the antenna array 700. Moreover, asexplained herein, some components of the BFN 800 can be formed ormounted on an exterior layer (e.g., a bottom layer) of the BFN 800. Forpurposes of simplification of explanation, the same reference numbersare employed in FIGS. 8 and 9 to denote the same structure. The BFN 800can be partitioned into a plurality of BFN cells 802 that are eachrotated in the global coordinate system 704. As noted, the BFN 800 canunderlay the antenna array 700 of FIG. 8. Moreover, each BFN cell 802can have the same size and shape (e.g., a square) as an overlayingantenna cell 702. Accordingly, the BFN cells 802 are labeled A-H tocorrespond to the overlaying antenna cell 702. Thus, BFN cell A 802underlies antenna cell A 702. Each BFN cell 802 can have the same localcoordinate system as the corresponding antenna cell 702.

Each BFN cell 802 can include N number of ports 714. In the exampleillustrated by the BFN 800, each BFN cell includes a first port 7141 anda second port 7142. Each port 714 can be representative of a terminal ofa via to a port illustrated in the antenna array 700. Each of the Nnumber of ports 714 can be at a same set of coordinates in eachrespective local coordinate system. As explained with respect to theantenna array 700, each of the N number of ports 714 can be at a sameset of coordinates in each local coordinate system.

Each of the N number of ports 714 can be environed by a plurality ofisolation vias 715, only some of which are labeled. The isolation vias715 can correspond to the isolation vias 715 of FIG. 8. Additionally, insome examples, some of the isolation vias 715 can extend only partiallybetween the BFN 800 and the antenna array 700 of FIG. 8.

The BFN 800 can include an I/O port 806 that can be coupled to anexternal system. The I/O port 806 can be coupled to a first stagecombiner/divider 808, which can be coupled to two (2) second stagecombiners/dividers 810 through vias 812. In some examples, the vias 812can be shorter than the vias of the ports 714. the first stagecombiner/divider 808 and the second stage combiners/dividers 810 canhave a cascade arrangement.

Each BFN cell 802 can correspond to an IC chip 820 (or multiple ICchips) that can adjust signals. Each IC chip 820 can be positioned onthe bottom layer of the BFN 800. In some examples, each IC chip 820 canbe integrated with the BFN 800, and in other examples, each IC chip 820can be a separate component that communicates with the BFN 800. Each ICchip 820 can be coupled to a second stage combiner/divider 810 and tothe N number of ports 714 of the BFN cell 802. Each IC chip 820 canamplify, phase adjust, combine and/or divide signals.

The second stage combiners/dividers 810 can be symmetrically arrangedrelative to the first stage 808. Moreover, in such a situation, BFNcells 802 and a second stage combiner/divider 810 can define a beamforming stage that has a local coordinate system. In this manner, eachbeam forming stage (a combination of BFN cells 802 and a second stagecombiner/divider 810) can have the same geometric shape in the localcoordinate system. Moreover, each beam forming stage can be rotated inthe global coordinate system 704.

The BFN 800 can operate in a manner similar to the BFN 200 of FIG. 2.Thus, the BFN 800 can operate in at least one of the transmitting modeand the receiving mode.

As illustrated with the antenna array 700 of FIG. 8 and the BFN 800 ofFIG. 9, the antenna cells 702 and the BFN cells 802 can communicatethrough the N number of ports 714. Moreover, the antenna array 700 canbe designed such that the slot elements 708 can be rotated independentlyfrom the location of the ports 714. Accordingly, the angle of rotationof the slot elements 708 does not necessarily impact the physical layoutof the BFN 800. Therefore, the BFN 800 and the antenna array 700 can bedesigned independently based on predetermined positions of each of the Nnumber of ports 714 for each BFN cell 802 and each antenna cell 702.Thus, the overall design of the BFN 800 and the antenna array 700 can besimplified.

In some examples, the BFN 800 can be designed systematically withsymmetric modules that are scalable to accommodate nearly any number oflevels. In particular, although the BFN 800 is described with two (2)stages of combiners/dividers, namely the first stage combiner/divider808 and the second stage combiners/dividers 810, the BFN 800 illustratedcan be employed as a module or circuit to implement a larger scale BFN,including the BFN 900 illustrated in FIG. 10.

In the BFN 900, eight (8) instances of the BFN 800 of FIG. 9 areconnected in a cascade (hierarchical) arrangement. In particular, an I/Oport 902 is coupled to a first stage combiner/divider 904, which caneach be coupled to two (2) second stage combiners/dividers 906. Eachsecond stage combiner/divider 906 can be coupled to two (2) third stagecombiners/dividers 908. Each third stage combiner/divider 908 can becoupled to two instances of an input port 806 of an instance of the BFN800 (a module of the BFN 900). In this manner, the eight (8) instancesof the BFN 900 are connected together in a cascade arrangement. Further,in other examples, multiple instances of the BFN 900 can be coupled in acascade arrangement.

FIG. 11 illustrates a stack-up (cross-sectional) view of a multi-layerPCB 1000 (or other dielectric substrate) that can include an antennaarray 1002 overlaying a BFN 1004 formed on a BFN layer. The multi-layerPCB 1000 can be employed to implement a system that can at least one oftransmit and receive RF signals. The antenna array 1002 can beimplemented, for example, with the antenna array 100 of FIG. 1, theantenna array 400 of FIG. 5 or the antenna array 700 of FIG. 8. The BFN1004 formed on the BFN layer can have a plurality of traces (e.g.,conductive traces). The BFN 1004 can be implemented, for example, as theBFN 200 of FIG. 2, the BFN 300 of FIG. 3, a portion of the BFN array 320of FIG. 4, the BFN 500 of FIG. 6, the BFN 600 of FIG. 7, the BFN 800 ofFIG. 9 or the BFN 900 of FIG. 10. In FIG. 11, a portion of themulti-layer PCB 1000 is included. The multi-layer PCB 1000 can includecore material (e.g., dielectric laminate) layers 1008, pre-preg material(a pre-impregnated material, such as an epoxy-based material) layers1010 and conductive material (e.g., ground plane) layers 1012.

An IC chip region 1014 can include layers for mounting an IC chip 1016onto a lower surface of the BFN 1004. The IC chip 1016 can beimplemented, for example, as an instance of the IC chip 220 of FIG. 2,the IC chip 520 of FIG. 6 or the IC chip 820 of FIG. 9. The multi-layerPCB 1000 can include a port 1018 implemented as a via thatcommunicatively couples the IC chip 1016 to the antenna array 1002. Themulti-layer PCB 1000 can also include an isolation via 1020 thatprovides shielding for the port 1018. The IC chip region 1014 cancommunicate with the BFN 1004 through a via 1022 that communicativelycouples a combiner/divider that can be formed on a bottom (exterior)layer of the BFN 1004 to the IC chip 1016. The combiner/divider can beimplemented, for example, as the 3-to-1 combiner/divider 212 of FIG. 2,the second stage combiner/divider 510 of FIG. 6 or the second stagecombiner divider 810 of FIG. 9. Additionally, the IC chip 1016 can beconnected to a power supply through a via 1026 that can couple the ICchip 1016 to direct current (DC) power supply region 1028 of themulti-layer PCB 1000. Further, the IC chip 1016 can be connected to anelectrically neutral node (e.g., ground) through a via 1030.

A feeder layer 1032 of the antenna array 100 can underlay radiatingelements 1034 of the antenna array 1002. The feeder layer 1032 caninclude an instance of a feedline 1036. The feed line 1036 can couplethe port 1018 to a slot element 1038 of the radiating elements 1034. Theslot element 1038 can be electromagnetically coupled to a patch antenna1039 of the radiating elements 1034.

FIG. 11 includes an arrow representing a signal 1040 flowing through themulti-layer PCB 1000 operating in the transmitting mode. The signal 1040can be provided, for example, as an electrical signal (a guided EMsignal) from an external system. The signal 1040 traverses thecombiner/divider 1024 and is provided to the IC chip 1016 through thevia 1022. The IC chip 1016 can adjust (e.g., amplify, phase adjustand/or divide) the signal 1040. Moreover, the signal 1040 can beprovided to the port 1018, and the signal 1040 is received at theantenna array 1002. The signal 1040 can be provided to the slot element1038 through the feedline 1036. The slot element 1038 can convert aguided EM signal into a radiated EM signal that is transmitted by thepatch antenna 1039 into free space. In the receiving mode, signalsoperate in reverse of the signal 1040.

FIG. 12 illustrates a block diagram of a system 1100 that depicts thelogical interconnection of an antenna array 1102 and a BFN 1104. Theantenna array 1002 can be implemented, for example, with the antennaarray 100 of FIG. 1, the antenna array 400 of FIG. 5 or the antennaarray 700 of FIG. 8. The BFN 1004 can be implemented, for example, asthe BFN 200 of FIG. 2, the BFN 300 of FIG. 3, the BFN 500 of FIG. 6, theBFN 600 of FIG. 7, the BFN 800 of FIG. 9 or the BFN 900 of FIG. 10.

In some examples, the antenna array 1102 can operate exclusively in thetransmitting mode or the receiving mode. In other examples, the antennaarray 1102 can operate in a half-duplexing mode, wherein the antennaarray 1102 switches between the receiving mode and the transmittingmode. In still other examples, the antenna array 1102 can operate in afull-duplexing mode, wherein the antenna array 1102 operatesconcurrently in the receiving mode and the transmitting mode.

In the illustrated example, K number of antenna cells 1106 communicatewith the BFN 1104, where K is an integer greater than or equal to two(2). Each of the K number of antenna cells 1106 can include a radiatingelement 1108. The radiating element 1108 can be representative of Nnumber of orthogonally arranged slot elements 1110 and a patch antenna1114. In the example illustrated there are two slot elements 1110,namely a first slot element 1110 ₁ and a second slot element 1110 ₂.Each of the K number of antenna cells 1106 can communicate with acorresponding IC chip 1116. In the illustrated example, each IC chip1116 can include a combiner/divider 1120 that can combine and/or dividesignals traversing the IC chip 1116. Additionally, each IC chip 1116 caninclude N number of paths for communicating with the N number of slotelements 1110 of the corresponding antenna cell 1106. In the presentexample, each IC chip 1116 can include a first path 1122 and a secondpath 1124. Additionally, in some examples, the first path 1122 and thesecond path 1124 of each IC chip 1116 can be representative of multiplepaths that can be further sub-divided into a receiving path and atransmitting path.

The first path 1122 and the second path 1124 can each include anamplifier 1130 and a phase shifter 1132 for adjusting signalscommunicated with the corresponding radiating element 1108 and/or theBFN 1104.

The first path 1122 can be coupled to a first port 11341 of thecorresponding antenna cell 1106 and the second path 1124 can be coupledto a second port 11342 of the corresponding antenna cell 1106. The firstport 11341 of the antenna cell 1106 can be designed to communicatesignals between the first path 1122 of the IC chip 1116 and the firstslot element 1110 ₁ that are in a first polarization. The second port11342 of the antenna cell 1106 can be designed to communicate signalsbetween the second slot element 1110 ₂ with a second polarization,orthogonal to the first polarization. For instance, the firstpolarization can be horizontal polarization and the second polarizationcan be vertical polarization, or vice versa. In such a situation, theantenna array 1102 can communicate signals with right hand circularpolarization (RHCP) or left hand circular polarization (LHCP).Alternatively, in some examples, there can be only one slot element1110, and the polarization can be a linear polarization.

The IC chips 1116 can receive control signals from a controller 1140that can be implemented on an external system. In some examples, thecontroller 1140 can be implemented as a microcontroller with embeddedinstructions. In other examples, the controller 1140 can be implementedas a general-purpose computer with software executing thereon. In someexamples, the control signals can control mode of operation of thesystem 1100. That is, in some examples, the control signals can causethe IC chips 1116 to switch the antenna array 1102 from the receivingmode to the transmitting mode, or vice-versa. Additionally, in someexamples, the control signals provided from the controller 1140 cancontrol a variable amount of amplitude adjustment applied by eachamplifier 1130. Thus, in some examples, each amplifier 1130 can beimplemented as a variable gain amplifier, a switched attenuator circuit,etc. Similarly, in some examples, the control signals provided from thecontroller 1140 can control a variable amount of phase adjustmentapplied by each phase shifter 1132.

During operation in the receiving mode, the controller 1140 can causethe IC chips 1116 to route signals from the K number of antenna cells1106 to the BFN 1104. Moreover, in the receiving mode, an EM signal (anRF signal) in the first polarization can be received at the patchantenna 1114 and detected by the first slot elements 1110 ₁ by each ofthe K number of antenna cells 1106 (or some subset thereof). Similarly,an EM signal (RF) in the second polarization can be received at thepatch antenna 1114 and detected by the second slot element 1110 ₂. Eachof the first slot elements 1110 ₁ and the second slot elements 1110 ₂can convert the received EM signals into an electrical signal that canbe provided to a corresponding IC chip 1116 for adjustment. Signalsprovided from the first slot element 1110 ₁ can be provided to the firstpath to the IC chip 1116 and signals provided from the second slotelement 1110 ₂ can be provided to the second path 1124 of the IC chip1116.

Continuing in the receiving mode, each amplifier 1130 in the first path1122 of the IC chips 1116 can amplify the signal provided from the firstslot element 1110 ₁ and each phase shifter 1132 of the first path 1122can apply a phase adjustment to output a signal to the combiner/divider1120. Similarly, each amplifier 1130 in the second path 1124 of the ICchips 1116 can amplify the signal provided from the second slot element1110 ₂ and each phase shifter 1132 of the second path 1124 can apply aphase adjustment to output a signal to the combiner/divider 1120. Eachcombiner/divider 1120 can combine a signal from the first path 1122 witha signal from the second path 1124, such that the K number of IC chips1116 can output K number of sub-signals. The K number of sub-signals canbe provided to the BFN 1104. The BFN 1104 can combine the K number ofsub-signals to form a received beam signal that can be provided to theexternal system for demodulating and processing.

During operation in the transmitting mode, the controller 1140 can setthe IC chips 1116 to provide a signal from the BFN 1104 to the K numberof antenna cells 1106. The K number of antenna cells 1106 can thustransmit a transmit beam signal that can be provided from the externalsystem to the BFN 1104. The BFN 1104 can divide the transmit beam signalinto K number of sub-signals that can be provided to the K number of ICchips 1116. Each IC chip 1116 of the K number of IC chips 1116 canadjust a corresponding sub-signal to generate an adjusted signal thatcan be provided to a corresponding antenna cell 1106. In the exampleillustrated, the adjusting can include dividing the correspondingsub-signal into a first signal and a second signal.

The first signal can be provided on the first path 1122 of the IC chip1116 and the second signal can be provided on the second path 1124 ofthe IC chip 1116. The phase shifter 1132 of the first path 1122 canapply a phase adjustment to the first signal and the amplifier 1130 ofthe first path 1122 can amplify the first signal. The first signal canbe provided to the first slot element 1110 ₁. The first slot element1110 ₁ can convert the first signal into an EM signal (an RF signal) inthe first polarization that can be transmitted to the patch antenna1114. Similarly, the phase shifter 1132 of the second path 1124 canapply a phase adjustment to the second signal and the amplifier 1130 ofthe second path 1124 can amplify the second signal. The second signalcan be provided to the second slot element 1110 ₂. The second slotelement 1110 ₂ can convert the second signal into an EM signal (an RFsignal) in the second polarization that can be transmitted to the patchantenna 1114. The patch antenna 1114 can transmit the EM signal in thefirst polarization and the EM signal in the second polarization intofree space.

What have been described above are examples. It is, of course, notpossible to describe every conceivable combination of components ormethodologies, but one of ordinary skill in the art will recognize thatmany further combinations and permutations are possible. Accordingly,the disclosure is intended to embrace all such alterations,modifications, and variations that fall within the scope of thisapplication, including the appended claims. As used herein, the term“includes” means includes but not limited to, the term “including” meansincluding but not limited to. The term “based on” means based at leastin part on. Additionally, where the disclosure or claims recite “a,”“an,” “a first,” or “another” element, or the equivalent thereof, itshould be interpreted to include one or more than one such element,neither requiring nor excluding two or more such elements.

What is claimed is:
 1. An antenna array comprising: a plurality ofantenna cells positioned in a global coordinate system of the antennaarray, wherein each of the plurality of antenna cells has a respectivelocal coordinate system and comprises: a radiating element having apredetermined angle of rotation defined in the global coordinate system;and an antenna port coupled to the radiating element, the antenna portbeing positioned at a particular set of coordinates in the respectivelocal coordinate system; wherein the particular set of coordinates ofthe antenna port of each of the plurality of antenna cells are the same;and wherein the predetermined angle of rotation of the radiating elementof a first antenna cell of the plurality of antenna cells is a firstrotation angle in the global coordinate system, and the predeterminedangle of rotation of the radiating element of a second antenna cell ofthe plurality of antenna cells is a second rotation angle in the globalcoordinate system, the second rotation angle different than the firstrotation angle.
 2. The antenna array of claim 1, wherein the antennaport of each of the plurality of antenna cells is a first antenna portand each of the plurality of antenna cells further comprises a secondantenna port, the second antenna port being positioned at a second setof coordinates in the respective local coordinate system, wherein thesecond antenna port of each of the plurality of antenna cells ispositioned at the same second set of coordinates in each respectivelocal coordinate system.
 3. The antenna array of claim 2, wherein thefirst antenna port and the second antenna port of each of the pluralityof antenna cells communicate signals that have a phase difference of 90degrees.
 4. The antenna array of claim 1, wherein the second antennacell is rotated in the global coordinate system relative to the firstantenna cell.
 5. The antenna array of claim 4, wherein the radiatingelement of the first antenna cell of the plurality of antenna cells hasa first local predetermined angle of rotation in the local coordinatesystem of the first antenna cell and the radiating element of the secondantenna cell of the plurality of antenna cells has a second localpredetermined angle of rotation in the local coordinate system of thesecond antenna cell, the second local predetermined angle of rotationbeing offset from the first local predetermined angle of rotation by apredetermined angle in the local coordinate system of the first antennacell and the local coordinate system of the second antenna cell.
 6. Theantenna array of claim 1, wherein a third antenna cell of the pluralityof antenna cells is rotated in the global coordinate system relative tothe first antenna cell of the plurality of antenna cells and a radiatingelement of the third antenna cell and the radiating element of the firstantenna cell are not rotated relative to each other in the globalcoordinate system.
 7. The antenna array of claim 1, wherein the antennaport of each of the plurality of antenna cells comprises a via that iscoupled to a beam-forming network (BFN).
 8. The antenna array of claim7, wherein the BFN comprises a plurality of combiners/dividers thatconvert between an input/output signal and a plurality of sub-signals,wherein each of the plurality of sub-signals is communicated to anantenna port of a respective antenna cell of the plurality of antennacells through an integrated circuit (IC) chip.
 9. The antenna array ofclaim 1, wherein the antenna port of each of the plurality of antennacells is a signal interface for communicating signals between theantenna cell and an integrated circuit (IC) chip coupled to abeam-forming network (BFN).
 10. The antenna array of claim 1, whereineach of the plurality of antenna cells further comprises a feedline thatcouples a corresponding radiating element and antenna port of arespective antenna cell, wherein a length of each respective feedline ofthe plurality of antenna cells is the same.
 11. The antenna array ofclaim 10, wherein a third antenna cell of the plurality of antenna cellsis rotated in the global coordinate system relative to the first antennacell of the plurality of antenna cells and a radiating element of thethird antenna cell and the radiating element of the first antenna cellare not rotated relative to each other in the global coordinate system.12. The antenna array of claim 1, wherein the particular set ofcoordinates for each of the plurality of antenna cells is locatedbetween a respective radiating element and a perimeter of a respectiveantenna cell.
 13. The antenna array of claim 1, further comprising aplurality of isolation vias, wherein a given isolation via of theplurality of isolation vias is shared between an antenna port of atleast three of the plurality of antenna cells.
 14. The antenna array ofclaim 1, wherein the antenna port of each of the plurality of antennacells is coupled to a beam-forming network (BFN) wherein the BFNcomprises a plurality of beam forming stages, wherein each of theplurality of beam forming stages has a respective local coordinatesystem, and each of the plurality of beam forming stages has the samegeometric shape in the respective local coordinate system; and wherein agiven beam forming stage of the plurality of beam forming stages has thesame geometric shape as another beam forming stage of the plurality ofbeam forming stages, wherein the given beam forming stage and the otherbeam forming stage are the same stage, and the given beam forming stageis rotated in the global coordinate system relative to the other beamforming stage.
 15. The antenna array of claim 1, wherein the pluralityof antenna cells are arranged in a plurality of groups of antenna cellseach comprises a group rotation pattern that defines a predeterminedangle of rotation in the global coordinate system for each radiatingelement in a respective group of antenna cells.
 16. The antenna array ofclaim 15, wherein the group rotation pattern for adjacent groups ofantenna cells is different.
 17. The antenna array of claim 1, whereinthe radiating element of six of the plurality of antenna cells has adifferent angle of rotation in the global coordinate system.
 18. Amulti-layer printed circuit board (PCB) comprising: a beam-forming layerhaving a plurality of traces that form a beam-forming network (BFN),wherein the beam-forming network is coupled to a plurality of antennaports forming vias extending away from the beam-forming network (BFN),the BFN comprises: a plurality of combiners/dividers that convertbetween an input/output signal and a plurality of sub-signals, whereineach of the plurality of sub-signals has an equal power and an array ofphases, wherein each of the plurality of sub-signals is communicated toan antenna port of the plurality of antenna ports; a plurality ofantenna cells being positioned in a global coordinate system of themulti-layered PCB to form a regular tiling pattern, wherein each of theplurality of antenna cells has a respective local coordinate system andcomprises: a radiating layer comprising a radiating element that has apredetermined angle of rotation in the global coordinate system; and afeedline layer having a feedline that couples a corresponding antennaport of the plurality of antenna ports to the radiating element, whereineach antenna port intersects with the feedline layer at a particular setof coordinates in the respective local coordinate system; wherein theparticular set of coordinates for each of the plurality of antenna cellsare the same; and wherein the predetermined angle of rotation of theradiating element of a first antenna cell of the plurality of antennacells is a first rotation angle in the global coordinate system, and thepredetermined angle of rotation of the radiating element of a secondantenna cell of the plurality of antenna cells is a second rotationangle in the global coordinate system, the second rotation angledifferent than the first rotation angle.
 19. The multi-layered PCB ofclaim 18, wherein the plurality of combiners/dividers of the BFN arearranged in a plurality of beam forming stages, wherein each of theplurality of beam forming stages has a respective local coordinatesystem, and each of the plurality of beam forming stages has the samegeometric shape in the respective local coordinate system; and wherein agiven beam forming stage of the plurality of beam forming stages has thesame geometric shape as another beam forming stage of the plurality ofbeam forming stages, wherein the given beam forming stage and the otherbeam forming stage are the same stage, and the given beam forming stageis rotated in the global coordinate system relative to the other beamforming stage.
 20. The multi-layered PCB of claim 18, wherein each ofthe plurality of beam forming stages correspond to a first circuit and asecond circuit, wherein the first circuit and the second circuit amplifyand phase shift a signal communicated between a respective beam formingstages and a corresponding radiating element of a respective antennacell of the plurality of antenna cells.